Devices, systems, and methods for retaining a native heart valve leaflet

ABSTRACT

Devices, systems and methods retain a native heart valve leaflet to prevent retrograde flow. The devices, systems, and methods employ an implant that, in use, rests adjacent a valve annulus and includes a retaining structure that is sized and shaped to overlay at least a portion of one or more native valve leaflets. The retaining structure retains the leaflet or leaflets it overlays, to resist leaflet eversion and/or prolapse. In this way, the implant prevents or reduces regurgitation. The implant does not interfere significantly with the opening of and blood flow through the leaflets during periods of antegrade flow.

RELATED APPLICATIONS

This application is a divisional of co-pending U.S. patent applicationSer. No. 10/676,729, filed Oct. 1, 2003, and entitled “Devices, Systems,and Methods for Retaining a Native Heart Valve Leaflet.”

This application is also a continuation-in-part of U.S. patentapplication Ser. No. 09/666,617, filed Sep. 20, 2000, now U.S. Pat. No.6,893,459 and dated May 17, 2005, and entitled “Heart Valve AnnulusDevice and Methods of Using Same.”

This application is also a continuation-in-part of Patent CooperationTreaty Application Serial No. PCT/US 02/31376, filed Oct. 1, 2002 andentitled “Systems and Devices for Heart Valve Treatments,” which claimedthe benefit of U.S. Provisional Patent Application Ser. No. 60/326,590,filed Oct. 1, 2001.

This application also claims the benefit of U.S. Provisional ApplicationSer. No. 60/429,444, filed Nov. 26, 2002, and entitled “Heart ValveRemodeling Devices;” U.S. Provisional Patent Application Ser. No.60/429,709, filed Nov. 26, 2002, and entitled “Neo-Leaflet MedicalDevices;” and U.S. Provisional Patent Application Ser. No. 60/429,462,filed Nov. 26, 2002, and entitled “Heart Valve Leaflet RetainingDevices,” all of the above which are each incorporated herein byreference.

FIELD OF THE INVENTION

The invention is directed to devices, systems, and methods for improvingthe function of a heart valve, e.g., in the treatment of mitral valveregurgitation.

BACKGROUND OF THE INVENTION I. The Anatomy of a Healthy Heart

The heart (see FIG. 1B) is slightly larger than a clenched fist. It is adouble (left and right side), self-adjusting muscular pump, the parts ofwhich work in unison to propel blood to all parts of the body. The rightside of the heart receives poorly oxygenated (“venous”) blood from thebody from the superior vena cava and inferior vena cava and pumps itthrough the pulmonary artery to the lungs for oxygenation. The left sidereceives well-oxygenation (“arterial”) blood from the lungs through thepulmonary veins and pumps it into the aorta for distribution to thebody.

The heart has four chambers, two on each side—the right and left atria,and the right and left ventricles. The atria are the blood-receivingchambers, which pump blood into the ventricles. A wall composed ofmembranous and muscular parts, called the interatrial septum, separatesthe right and left atria. The ventricles are the blood-dischargingchambers. A wall composed of membranous and muscular parts, called theinterventricular septum, separates the right and left ventricles.

The synchronous pumping actions of the left and right sides of the heartconstitute the cardiac cycle. The cycle begins with a period ofventricular relaxation, called ventricular diastole. The cycle ends witha period of ventricular contraction, called ventricular systole.

The heart has four valves (see FIGS. 1B and 1C) that ensure that blooddoes not flow in the wrong direction during the cardiac cycle; that is,to ensure that the blood does not back flow from the ventricles into thecorresponding atria, or back flow from the arteries into thecorresponding ventricles. The valve between the left atrium and the leftventricle is the mitral valve. The valve between the right atrium andthe right ventricle is the tricuspid valve. The pulmonary valve is atthe opening of the pulmonary artery. The aortic valve is at the openingof the aorta.

At the beginning of ventricular diastole (i.e., ventricular filling)(see FIG. 1B), the aortic and pulmonary valves are closed to preventback flow from the arteries into the ventricles. Shortly thereafter, thetricuspid and mitral valves open (as FIG. 1B shows), to allow flow fromthe atria into the corresponding ventricles. Shortly after ventricularsystole (i.e., ventricular emptying) begins, the tricuspid and mitralvalves close (see FIG. 1C)—to prevent back flow from the ventricles intothe corresponding atria—and the aortic and pulmonary valves open—topermit discharge of blood into the arteries from the correspondingventricles.

The opening and closing of heart valves occur primarily as a result ofpressure differences. For example, the opening and closing of the mitralvalve occurs as a result of the pressure differences between the leftatrium and the left ventricle. During ventricular diastole, whenventricles are relaxed, the venous return of blood from the pulmonaryveins into the left atrium causes the pressure in the atrium to exceedthat in the ventricle. As a result, the mitral valve opens, allowingblood to enter the ventricle. As the ventricle contracts duringventricular systole, the intraventricular pressure rises above thepressure in the atrium and pushes the mitral valve shut.

FIG. 1D shows a posterior oblique cutaway view of a healthy human heart100. Two of the four heart chambers are shown, the left atrium 170, andthe left ventricle 140 (not shown are the right atrium and rightventricle). The left atrium 170 fills with blood from the pulmonaryveins. The blood then passes through the mitral valve (also known as thebicuspid valve, and more generally known as an atrioventricular valve)during ventricular diastole and into the left ventricle 140. Duringventricular systole, the blood is then ejected out of the left ventricle140 through the aortic valve 150 and into the aorta 160. At this time,the mitral valve should be shut so that blood is not regurgitated backinto the left atrium.

The mitral valve consists of two leaflets, an anterior leaflet 110, anda posterior leaflet 115, attached to chordae tendineae 120 (or chords),which in turn are connected to papillary muscles 130 within the leftatrium 140. Typically, the mitral valve has a D-shaped anterior leaflet110 oriented toward the aortic valve, with a crescent shaped posteriorleaflet 115. The leaflets intersect with the atrium 170 at the mitralannulus 190.

In a healthy heart, these muscles and their chords support the mitraland tricuspid valves, allowing the leaflets to resist the high pressuredeveloped during contractions (pumping) of the left and rightventricles. In a healthy heart, the chords become taut, preventing theleaflets from being forced into the left or right atria and everted.Prolapse is a term used to describe the condition wherein the coaptationedges of each leaflet initially may coapt and close, but then theleaflets rise higher and the edges separate and the valve leaks. This isnormally prevented by contraction of the papillary muscles and thenormal length of the chords. Contraction of the papillary muscles issimultaneous with the contraction of the ventricle and serves to keephealthy valve leaflets tightly shut at peak contraction pressuresexerted by the ventricle.

II. Characteristics and Causes of Mitral Valve Dysfunction

Valve malfunction can result from the chords becoming stretched, and insome cases tearing. When a chord tears, the result is a flailed leaflet.Also, a normally structured valve may not function properly because ofan enlargement of the valve annulus pulling the leaflets apart. Thiscondition is referred to as a dilation of the annulus and generallyresults from heart muscle failure. In addition, the valve may bedefective at birth or because of an acquired disease, usually infectiousor inflammatory.

FIG. 2 shows a cutaway view of a human heart 200 with a prolapsed mitralvalve. The prolapsed valve does not form a tight seal during ventricularsystole, and thus allows blood to be regurgitated back into the leftatrium during ventricular contraction. The anterior 220 and posterior225 leaflets are shown rising higher than normal (i.e., prolapsing) intothe left atrium. The arrows indicate the direction of regurgitant flow.Among other causes, regurgitation can result from redundant valveleaflet tissue or from stretched chords 210 that are too long to preventthe leaflets from being blown into the atrium. As a result, the leafletsdo not form a tight seal, and blood is regurgitated into the atrium.

FIG. 3 shows a cutaway view of a human heart 300 with a flailing mitralvalve 320. The flailing valve also does not form a tight seal duringventricular systole. Blood thus regurgitates back into the left atriumduring ventricular contraction, as indicated by the arrows. Among othercauses, regurgitation can also result from torn chords 310.

As a result of regurgitation, “extra” blood back flows into the leftatrium. During subsequent ventricular diastole (when the heart relaxes),this “extra” blood returns to the left ventricle, creating a volumeoverload, i.e., too much blood in the left ventricle. During subsequentventricular systole (when the heart contracts), there is more blood inthe ventricle than expected. This means that: (1) the heart must pumpharder to move the extra blood; (2) too little blood may move from theheart to the rest of the body; and (3) over time, the left ventricle maybegin to stretch and enlarge to accommodate the larger volume of blood,and the left ventricle may become weaker.

Although mild cases of mitral valve regurgitation result in fewproblems, more severe and chronic cases eventually weaken the heart andcan result in heart failure. Mitral valve regurgitation can be an acuteor chronic condition. It is sometimes called mitral insufficiency.

III. Prior Treatment Modalities

In the treatment of mitral valve regurgitation, diuretics and/orvasodilators can be used to help reduce the amount of blood flowing backinto the left atrium. An intra-aortic balloon counterpulsation device isused if the condition is not stabilized with medications. For chronic oracute mitral valve regurgitation, surgery to repair or replace themitral valve is often necessary.

To date, invasive, open heart surgical approaches have been used torepair or replace the mitral valve with either a mechanical valve orbiological tissue (bioprosthetic) taken from pigs, cows or horses.

The need remains for simple, cost-effective, and less invasive devices,systems, and methods for treating dysfunction of a heart valve, e.g., inthe treatment of mitral valve regurgitation.

SUMMARY OF THE INVENTION

The invention provides devices, systems and methods that retain a nativeheart valve leaflet. The devices, systems, and methods include animplant that, in use, rests adjacent all or a portion of a valveannulus. The implant includes a retaining structure that is shaped tooverlay at least a portion of one or more native valve leaflets. Theimplant further includes spaced-apart struts sized and configured tocontact tissue near or within the heart valve annulus. The struts bracethe retaining structure to resist leaflet eversion and/or prolapse. Inthis way, the implant prevents or reduces retrograde flow andregurgitation. The implant does not interfere with the opening of andblood flow through the leaflets during antegrade flow.

Other features and advantages of the invention shall be apparent basedupon the accompanying description, drawings, and claims.

DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective, anterior anatomic view of the interior of ahealthy heart.

FIG. 1B is a superior anatomic view of the interior of a healthy heart,with the atria removed, showing the condition of the heart valves duringventricular diastole.

FIG. 1C is a superior anatomic view of the interior of a healthy heart,with the atria removed, showing the condition of the heart valves duringventricular systole.

FIG. 1D is a posterior oblique cutaway view of a portion of a humanheart, showing a healthy mitral valve during ventricular systole, withthe leaflets properly coapting.

FIG. 2 is a posterior oblique cutaway view of a portion of a humanheart, showing a dysfunctional mitral valve during ventricular systole,with the leaflets not properly coapting, causing regurgitation.

FIG. 3 is a posterior oblique cutaway view of a portion of a humanheart, showing a dysfunctional mitral valve during ventricular systole,with the leaflets flailing, causing regurgitation.

FIG. 4 is a perspective, anatomic view of a wire form implant thatincludes a retaining element to resist eversion and/or prolapse of anative valve leaflet, the implant being shown installed on a mitralvalve annulus.

FIG. 5 is a side elevation view of the implant shown in FIG. 4, shownoutside of the body.

FIG. 6 is a top view of the implant shown in FIG. 4, shown outside thebody.

FIG. 7 is a top view of another illustrative wire form implant of thetype shown in FIG. 6.

FIGS. 8 and 9 are top views of illustrative wire form implants of thetype shown in FIGS. 4 and 5, which include retaining elements to resisteversion and/or prolapse of a native valve leaflet, and which alsoinclude both infra-annular struts and tabs and supra-annular pads to fixthe position of the implants in a valve annulus.

FIG. 10 is a perspective view of the implant shown in FIG. 9.

FIG. 11 is a perspective, anatomic view of the wire form implant shownin FIG. 10, the implant being shown installed on a mitral valve annulus.

FIGS. 12 to 14 are perspective, anatomic views showing the intravascularintroduction and deployment of the implant shown in FIG. 11 on a mitralvalve annulus.

FIG. 15 is a perspective view of an illustrative wire form implant ofthe type shown in FIGS. 4 and 5, which include retaining elements toresist eversion and/or prolapse of a native valve leaflet, and whichalso include frameworks to orient and stabilize the position of theimplants in a valve annulus.

FIG. 16 is a top view of wire-form mesh implant that resists eversionand/or prolapse of a native valve leaflet.

FIG. 17 is a perspective, anatomic view of the wire-form mesh implantshown in FIG. 16 installed on a mitral valve annulus.

FIGS. 18 and 19 are top views of illustrative embodiments of implants ofthe types shown in FIGS. 5 and 6, showing implants that are narrow anddo not peripherally rest on the entire valve annulus.

FIG. 20 is a top view of an illustrative embodiment of a wire-form meshimplant of the type shown in FIGS. 16 and 17, being shown in a flattenedcondition for intravascular deployment, which, upon deployment, resistseversion and/or prolapse of a native valve leaflet, and which alsoinclude an auxiliary structure to orient and stabilize the position ofthe implants in a valve annulus, the implant in FIG. 20 also includinginfra-annular struts and tabs to fix the position of the implant in thevalve annulus.

FIG. 21 is a perspective, anatomic view of the wire-form mesh implantshown in FIG. 20, installed on a mitral valve annulus.

FIGS. 22, 23, and 24 are top views of illustrative embodiments ofwire-form mesh implants of the type shown in FIG. 20, which resisteversion and/or prolapse of a native valve leaflet, and which alsoinclude a combination of auxiliary structures and infra-annular strutsand tabs to fix, orient, and stabilize the position of the implants in avalve annulus, the implants being shown in a flattened condition forintravascular deployment.

FIG. 25 is a perspective view of illustrative embodiments of wire-formmesh implants of the type shown in FIG. 20, which resist eversion and/orprolapse of a native valve leaflet, and which also include a combinationof auxiliary structures and infra-annular struts and tabs to fix,orient, and stabilize the position of the implants in a valve annulus,the implants being shown in an expanded condition after intravasculardeployment.

DETAILED DESCRIPTION

Although the disclosure hereof is detailed and exact to enable thoseskilled in the art to practice the invention, the physical embodimentsherein disclosed merely exemplify the invention, which may be embodiedin other specific structure. While the preferred embodiment has beendescribed, the details may be changed without departing from theinvention, which is defined by the claims.

I. Implants for Retaining a Native Heart Valve Implant

A. Planar Wire-Form Implants

1. Overview

FIGS. 4, 5, and 6 show an implant 400 sized and configured to retain atleast one dysfunctional native heart valve leaflet. In use (see, inparticular, FIG. 4), the implant 400 rests adjacent all or a portion ofthe native heart valve annulus, which, in FIG. 4, is in the atrium. Theimplant 400 includes a scaffold 410, at least a portion of which definesa pseudo-annulus. The scaffold 410 includes a retaining element 420 ator near the pseudo-annulus. The retaining element 420 is sized andshaped to overlay at least a portion of the superior surface at leastone native valve leaflet. The implant 400 allows the native leaflets tocoexist with the implant 400.

In its most basic form, the components of the implant 400 are made—e.g.,by bending, shaping, joining, machining, molding, or extrusion—from abiocompatible metallic or polymer material, or a metallic or polymermaterial that is suitably coated, impregnated, or otherwise treated witha material or combination of materials to impart biocompatibility. Thematerial is also desirably radio-opaque to facilitate fluoroscopicvisualization. The implant material may be rigid, semi-rigid, orflexible.

In the embodiment shown in FIG. 4, the scaffold 410 is sized andconfigured to rest adjacent all or a portion of the mitral annulus inthe atrium. In the illustrated embodiment (FIG. 4), the scaffold 410forms an annular body that, at least in part, approximates the shape ofthe native annulus. For this reason, at least a portion of the scaffold410 is said to define a pseudo-annulus. The scaffold 410 includes theretaining element 420, which extends from the periphery of the scaffold410 radially into the pseudo-annulus.

The retaining element 420 is sized and configured (see FIG. 4) tooverlay the superior surface of at least one native valve leaflet. Inthe illustrated embodiment, the retaining element 420 overlays regionsof both leaflets. However, the retaining element 420 could be sized,configured, and oriented to overlay all or a portion of one leaflet orboth leaflets. The size, configuration, and orientation of the retainingelement 420 can vary, depending on patient needs, as will be describedin greater detail later.

When installed adjacent a mitral valve annulus, during ventricularsystole the retaining element 420 exerts a restraining force on thesuperior surface of the leaflet or leaflets it overlays, resistingdeflection of the leaflet or leaflets into the atrium and preventingleaflet eversion and/or prolapse as well as retrograde flow of bloodthrough the valve during ventricular systole from the ventricle into theatrium. The restraining force also serves to keep valve leaflets tightlyshut during peak ventricular systolic pressures. The retaining element420 thus serves as a “backstop” for the leaflet or leaflets it overlays.During ventricular diastole this restraining force goes to zero and theretaining element 420 does not prevent opening of the native valveleaflet or leaflets during antegrade flow. During ventricular diastole,the native valve leaflet or leaflets open normally so that blood flowoccurs from the atrium into the ventricle. The implant 400 therebyrestores normal one-way function to the valve.

As shown in FIGS. 5 and 6, in the illustrated embodiment, the scaffold410 and the retaining element 420 are shaped from a continuous length ofwire-formed material. The shape and materials of the scaffold 410 andretaining element 420 provide the implant 400 with spring-likecharacteristics. The retaining element 420 is shaped so that, duringventricular systole, it elastically resists eversion and/or prolapse ofthe leaflet or leaflets.

2. Fixation of Implants

The spring-like bias of the implant 400 facilitates compliant fixationof the outer periphery of the implant 400 to or near the annulus. Thescaffold 410 of the implant 400 dynamically conforms to the shape of theanatomy.

As FIGS. 5 and 6 show, the scaffold 410 can also include supra-annularcontact structures 440. The structures 440 are appended to the scaffold410 to provide multiple contact regions between the implant 400 and theatrial wall, above the valve annulus. The multiple regions of contactthat the structures 440 provide uniformly distributes the resting forcesof the implant, and help to prevent erosion of the atrial walls andmigration of the implant.

Alternatively or in combination with the supra-annular structures 440,the implant 400 can include infra-annular contact struts 430. The struts430 are appended to the scaffold 410, extending below the plane of theannulus into the ventricular chamber. The struts 430 are preferablyconfigured to extend through the valve orifice on narrow connectingmembers, so that they will not interfere with the opening and closing ofthe valve. The struts 430 fix and stabilize the implant within theannulus.

In this arrangement, the struts 430 are desirably sized and configuredto contact tissue near or within the mitral valve annulus to brace theretaining structure 420 to resist leaflet eversion and/or prolapseduring ventricular systole. In this arrangement, it is also desirablethat the scaffold 410 be “elastic,” i.e., the material of the scaffold410 is selected to possess a desired spring constant. This means thatthe scaffold 410 is sized and configured to possess a normal, unloaded,shape or condition, in which the scaffold 410 is not in net compression,and the struts 450 are spaced apart farther than the longestcross-annulus distance between the tissue that the struts 430 areintended to contact. In the illustrated embodiment (FIG. 4), thescaffold 410 shown resting along the major (i.e., longest) axis of themitral valve annulus, with the struts 430 contact tissue at or near theleaflet commissures. However, other orientations are possible. Thestruts 430 need not rest at or near the leaflet commissures, but may besignificantly removed from the commissures, so as to gain padding fromthe leaflets. The spring constant imparts to the scaffold 410 theability to be elastically compressed out of its normal, unloadedcondition, in response to external compression forces applied at thestruts 430. The scaffold 410 is sized and configured to assume anelastically loaded, in net compression condition, during which thestruts 430 are spaced apart a sufficiently shorter distance to rest inengagement with tissue at or near the leaflet commissures (or wherevertissue contact with the struts 430 is intended to occur) (see FIG. 9A or9B). When in its elastically loaded, net compressed condition (see FIGS.9A and 9B), the scaffold 410 can exert forces to the tissues through thestruts 430. These forces hold the scaffold 410 (and thus the retainingelement 420 itself) against migration within the annulus. Furthermore,when the struts 430 are positioned at or near the commissures, they tendto outwardly displace tissue and separate tissue along the major axis ofthe annulus, which also typically stretches the leaflet commissures,shortens the minor axis, and/or reshapes surrounding anatomicstructures. The scaffold 410 can also thereby reshape the valve annulustoward a shape more conducive to leaflet coaptation. It should beappreciated that, in order to be therapeutic, the implant 400 may onlyneed to reshape the annulus during a portion of the heart cycle, such asduring ventricular systolic contraction. For example, the implant may besized to produce small or negligible outward displacement of tissueduring ventricular diastole when the tissue is relaxed, but restrict theinward movement of tissue during ventricular systolic contraction.

As just described, different forms of heart valve treatment can beprovided using a single implant 400.

Implants having one or more of the technical features just described, tothereby function in situ as a backstop or retainer for native leaflets,may be sized and configured in various ways. Various illustrativeembodiments will now be described.

FIG. 7 shows another illustrative embodiment of an implant 400 includinga scaffold 410 that defines a pseudo-annulus and a retaining element 420that functions as a leaflet retainer 420. In FIG. 7, the implant 400 isshown in a flattened condition. The implant 400 includes infra-annularstruts 430. Upon deployment, the struts 430 contact tissue near orwithin the heart valve annulus, and, in particular, between or nearlybetween the commissures of the leaflets, and extend into the ventricularside of the valve. As before described, the struts 430 function to braceand secure the implant in situ.

FIG. 8 shows yet another illustrative embodiment of an implant 400including a scaffold 410 that defines a pseudo-annulus and a retainingelement 420 that functions as a leaflet retainer. The implant 400 alsoincludes infra-annular struts 430. In addition, the implant 400 includessupra-annular contact structures 440, used to disperse the loadsexperienced by the implant throughout the atrium.

FIG. 9 shows other illustrative embodiment of an implant 400 including ascaffold 410 that defines a pseudo-annulus and a retaining element 420that functions as a leaflet retainer. In FIGS. 8 and 9, the retainingelement 420 extends across the interior of the implant in a figure eightpattern and has two support struts 430. Like the implant shown in FIG.8, the implant 400 in FIG. 9 includes a plurality of infra-annularstruts 430 and a plurality of supra-annular contact structures 440 thatbrace, fix, and stabilize the implants in situ.

As can be seen in the perspective view in FIG. 10, one or more of thestruts 430 can include a superior component that rests on the atrialside of the valve, and an inferior component that rests on theventricular side of the valve (see FIG. 11). In this arrangement, thestruts 430 place the implant near or within a heart valve annulus, e.g.,between the commissures of the leaflets. As before described, the shapeand tension of the scaffold 410 can apply a force through the struts 430that outwardly displaces tissue and stretches the annulus. Thedisplacement of the tissue can remodel the annulus and promote normalvalve function, free of eversion and/or prolapse, through a differentmechanism than the retaining elements 420.

Any number of supra-annular contact structures 440 can also be used, todisperse the loads experienced by the implant throughout the atrium.

As FIG. 15 shows, a given implant 400 can include one or more auxiliarystructures 450 to orient and stabilize the implant 400 within the leftatrium. In FIG. 15, the implant 400 includes, in addition to thescaffold 410 and the retaining element 420, an orientation andstabilization framework 450. The framework 450 rises from the scaffold410 above the retaining element 420, e.g., with two substantiallyparallel arched wires, which connect to form a semicircular hoop abovethe restraining element 420. The framework 450 helps to accuratelyposition the implant 400 within the atrium, and also helps to secure theimplant 400 within the atrium.

Preferably the framework 450 does not interfere with atrial function,but instead is compliant enough to contract with the atrium. As such,the implant 400 may have nonuniform flexibility to improve its functionwithin the heart.

Additionally, the implant 400 of FIG. 15 has infra-annular struts 430that contact tissue near or within the heart valve annulus to brace theimplant 400 and assist in positioning and anchoring of the implant.

The implant 400 may be additionally fixed to the annulus in variousauxiliary ways. For example, the implant 400 may be secured to theannulus with sutures or other attachment means (i.e. barbs, hooks,staples, etc.). Still, the position and orientation of the implant isdesirably braced or fixed by structures appended to or carried by theimplant itself, obviating reliance upon such auxiliary fixationmeasures.

In FIG. 15, the retaining element 420 is sized and configured to coverthe superior surface of a single leaflet.

FIGS. 18 and 19 show other illustrative embodiments of implants 400sized and configured to function as leaflet retainers. In theseembodiment, each implant 400 includes a narrow leaflet retaining element420. The narrow leaflet retaining elements 420 span the annulus, but theassociated scaffold 410 need not peripherally follow the entire annulus.

3. Deployment of Wire Form Implants

The implant 400 may be delivered percutaneously, thoracoscopicallythrough the chest, or using open heart surgical techniques. If deliveredpercutaneously, the implant 400 may be made from a superelastic material(for example superelastic Nitinol alloy) enabling it to be folded andcollapsed such that it can be delivered in a catheter, and willsubsequently self-expand into the desired shape and tension whenreleased from the catheter. The deployment of an implant in this fashionwill now be described.

FIGS. 12 to 14 show a sequence of steps for a catheter-based,percutaneous deployment of an implant 400 having the technical featuresdescribed. Percutaneous vascular access is achieved by conventionalmethods into the femoral or jugular vein. Under image guidance (e.g.,fluoroscopic, ultrasonic, magnetic resonance, computed tomography, orcombinations thereof), a first catheter (not shown) is steered throughthe vasculature into the right atrium. A needle cannula carried on thedistal end of the first catheter is deployed to pierce the septumbetween the right and left atrium. A guide wire 1710 is advancedtrans-septally through the needle catheter into the left atrium. Thefirst catheter is withdrawn, leaving the guide wire 1710 behind. FIG. 12shows the guide wire 1710 introduced through the vena cava 1730 and intothe right atrium, and then through the septum 1720 between the right andleft atriums, into the left atrium.

As FIG. 13 shows, under image guidance, an implant delivery catheter1820 is advanced over the guide wire 1710 into the left atrium intoproximity with the mitral valve. Alternatively, the implant deliverycatheter 58 can be deployed trans-septally by means of surgical accessthrough the right atrium.

The implant delivery catheter 1820 carries within it a wire-form implant400 of a type shown in FIGS. 10 and 11, previously described. Theimplant 10 is constrained within the catheter 1820 in a collapsed,straightened condition. A push rod within the catheter 1820 expels theimplant (see FIG. 13). Free of the catheter 1820, the implant 400 willexpand, as FIG. 14 shows. Progressively freed from the catheter 1820,the implant 400 shapes and seats about the annulus, as the struts 430seat within the commissures and the retaining elements 420 extend overthe leaflets. The implant can also be positioned or repositioned underimage guidance within the left atrium using a catheter-deployed graspinginstrument.

B. Wire-Form Mesh Implants

FIGS. 16 and 17 show another embodiment of an implant 400 including ascaffold 410 that defines a pseudo-annulus and a retaining element 420that functions as a leaflet retainer. In this embodiment, the retainingelement 420 includes wire-form mesh that has been shaped to fit theheart anatomy (see FIG. 16). The wire-form mesh can be secured withinthe atrium with sutures or other attachment means (i.e. barbs, hooks,staples, etc.). Alternatively, the body of the wire-form mesh can besecured by spring action between the body of the implant and the wallsof the heart.

In FIG. 20, another illustrative embodiment of an implant 400 includinga scaffold 410 that defines a pseudo-annulus and a retaining element420. The implant 400 is shown in a flattened out condition. FIG. 21shows the implant 400 shown in FIG. 20 after deployment in a leftatrium. The implant 400 includes a leaflet retaining element 420,upwardly extending stabilization arch structures 440, as well asinfra-annular struts 430, shaped and configured as previously described.The arch structures 440 and struts 430 cooperate to orient and stabilizethe implant in the desired position for retaining the valve leaflets.

FIGS. 22, 23, and 24 show illustrative embodiments of other implants 400of the type shown in FIGS. 20 and 21 in flattened out conditions. Eachof these implants 400 include a scaffold 410 that defines apseudo-annulus and a retaining element 420. In these embodiments, theimplants 400 include, in addition to a leaflet retaining element 420, aplurality of arch structures 440 that, when deployed, contact theinterior of the atrium to support and align the implant 400, as well asinfra-annular struts 430 that contact tissue near or within the heartvalve annulus to brace the retaining structure 420 to resist leafleteversion and/or prolapse during ventricular systole. FIG. 25 showsvarious illustrative embodiments of an implant 400 in a deployedconditioned.

While the new devices and methods have been more specifically describedin the context of the treatment of a mitral heart valve, it should beunderstood that other heart valve types can be treated in the same orequivalent fashion. By way of example, and not by limitation, thepresent systems and methods could be used to resist or preventretrograde flow in any heart valve annulus, including the tricuspidvalve, the pulmonary valve, or the aortic valve. In addition, otherembodiments and uses of the invention will be apparent to those skilledin the art from consideration of the specification and practice of theinvention disclosed herein. The specification and examples should beconsidered exemplary and merely descriptive of key technical featuresand principles, and are not meant to be limiting. The true scope andspirit of the invention are defined by the following claims. As will beeasily understood by those of ordinary skill in the art, variations andmodifications of each of the disclosed embodiments can be easily madewithin the scope of this invention as defined by the following claims.

1. An implant that retains a native heart valve leaflet to resistretrograde flow comprising: a scaffold sized and configured to restadjacent all or a portion of a native heart valve annulus, at least aportion of the scaffold defining a pseudo-annulus and including aretaining structure near or within the pseudo-annulus that is sized andshaped to overlay at least a portion of one or more native valveleaflets, and the scaffold further including spaced-apart struts sizedand configured to contact tissue near or within the heart valve annulusto brace the retaining structure to resist leaflet eversion and/orprolapse.
 2. An implant according to claim 1 wherein the retainingstructure comprises a wire-form structure.
 3. An implant according toclaim 1 wherein at least one of the struts comprises a wire-formstructure.
 4. An implant according to claim 1 wherein the retainingstructure and the struts each comprises a wire-form structure.
 5. Animplant according to claim 1 wherein the scaffold is collapsible forplacement within a catheter.
 6. An implant according to claim 1 whereinat least one of the struts carries a structure sized and configured toincrease a surface area of contact with tissue at, above, or below theannulus.
 7. An implant according to claim 1 further including at leastone structure appended to the scaffold and being sized and configured tocontact tissue at, above, or below the heart valve annulus to stabilizethe scaffold.
 8. An implant according to claim 1 wherein the scaffoldincludes a material and a shape to provide a spring-like bias to enablecompliant contact with tissue near or within the heart valve annulus. 9.An implant according to claim 1 wherein the struts reshape the heartvalve annulus.
 10. An implant according to claim 1 wherein the strutsapply tension to tissue to reshape the heart valve annulus.
 11. Animplant according to claim 1 wherein the struts displace tissue toreshape the heart valve annulus.
 12. An implant according to claim 1further including a second heart valve treatment element appended to thescaffold to affect a heart valve function.
 13. An implant according toclaim 12 wherein the second heart valve treatment element includes meansfor reshaping the heart valve annulus for leaflet coaptation.
 14. Animplant according to claim 12 wherein the second heart valve treatmentelement includes means for separating tissue along an axis of the heartvalve annulus for leafleted coaptation.